The present invention relates to an apparatus for detecting the angular position of an engine or the like, and more particularly the invention relates to an apparatus for detecting the angular position of an engine or the like stably against variations in the rotational speed thereof.
A detecting apparatus of this type is known in the art in which a magnetic member with a coil wound thereon is arranged opposite to a rotating member having high magnetic permeability, an alternating electromotive force is induced in the coil in response to the variation of the magnetic flux caused by the projections and notches on the rotating member, thereby detecting the rotation of the rotating member. A disadvantage of this type of apparatus is that, since the alternating electromotive force induced in the coil is affected by the variation of the magnetic flux which is dependent on the rotational speed of the rotating member, no alternating electromotive force is produced practically when the rotational speed of the rotating member is low.